What is the hybridization state of the central atom in the conjugate base of $NH_4^{+}$ ion?

What is the correct order of carbon-carbon bond length in the following molecules?

The correct order of bond angle is:

The types of hybrid orbitals of nitrogen in $NO_2^{+}$,$NO_3^{-}$ and $NH_4^{+}$ respectively are

Which set of hybridisation is correct for the following compounds:
$NO_2$,$SF_4$,$PF_6^-$

Is there any change in the hybridisation of $B$ and $N$ atoms as a result of the following reaction?
$BF_{3} + NH_{3} \rightarrow F_{3}B \cdot NH_{3}$